%I A048921
%S A048921 1,26884,542041975,10928650279834,220343446399977901,
%T A048921 4442564555387704166896,89570986345383445012986019,
%U A048921 1805930222253056462964119954950,36411165051495138060899141518722649
%N A048921 9-gonal heptagonal numbers (A000566).
%H A048921 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               NonagonalHeptagonalNumber.html">Link to a section of The World of 
               Mathematics.</a>
%Y A048921 Cf. A048919, A048920.
%Y A048921 Sequence in context: A093180 A093181 A051025 this_sequence A162144 A159995 
               A037045
%Y A048921 Adjacent sequences: A048918 A048919 A048920 this_sequence A048922 A048923 
               A048924
%K A048921 nonn
%O A048921 1,2
%A A048921 Eric Weisstein (eric(AT)weisstein.com)